Handheld mobile light source

ABSTRACT

In one aspect, a handheld lighting system is disclosed, which comprises a handheld housing extending from a proximal end to a distal end, and a light module disposed at least partially in the housing. The handheld lighting system further includes a removable and replaceable power module that is coupled to the housing (e.g., it is at least partially disposed within the housing) and is electrically coupled to the light module, e.g., through a pair of electrical leads, for providing electrical power thereto. Light intensity from the light module may be controlled from a knob on the power module. Various adapters can allow the lighting system to attach to a multitude of medical, industrial, dental or veterinary endoscopes or other instruments.

RELATED APPLICATIONS

The present application claims priority to a provisional patentapplication entitled “Handheld mobile light source” having anapplication No. 62/247,456 filed on Oct. 28, 2015, and a provisionalpatent application entitled “Embeddable module for high output LED”having an application No. 62/247,454 filed on Oct. 28, 2015, and aprovisional patent application entitled “Elliptical optical lens forhigh output LED” having an application No. 62/247,451 filed on Oct. 28,2015, each of which is herein incorporated by reference in its entirety.

The present application is also related to utility applications entitled“Embeddable module for high output LED” and “Elliptical optical lens forhigh output LED,” which are being filed concurrently herewith and arehereby incorporated by reference in their entirety.

BACKGROUND

The present invention relates generally to a handheld lighting systemthat can be mechanically coupled to a variety of devices, such asmedical and industrial endoscopes, to provide high intensity, low heatlight.

Many devices that operate in small, closed areas, require a light sourceto operate. For example, laparoscopic and endoscopic procedures areconducted through small incisions in the skin or natural body orifices.In order to operate or view an internal area, medical professionals useendoscopes that have small, elongated distal portions that fit withinthese small openings but are long enough to reach the internal areaswithin the body. These instruments need to provide precise and accuratemovement in order to reach areas within the body that are difficult toaccess. The distal working ends of the endoscopes usually contain asmall camera that allows a medical professional to view an internal areawithin the body during the procedure. The camera and the working end ofthe endoscope must have adequate remotely controlled illumination topermit the medical professional to view the internal area. In someendoscopes, a camera positioned outside the patient's body can receive,via a light guide, radiation reflected from an illuminated internal areaand form an image of that area for viewing by a medical professional.

Many conventional light sources are inefficient in converting electricalpower to light, and must be connected to external power sources,limiting their range of motion. Light emitting diodes (LED) can producelight without generating a large amount a heat, but they are nottypically capable of generating enough illumination to be useful in avariety of applications, such as endoscopic systems. Even if multipleLEDs are employed, in many conventional systems, the inefficientcoupling of the light generated by the LEDs into a light guide of adevice can result in insufficient intensity.

Accordingly, there is a need for enhanced lighting systems, andparticularly a need for such systems that can be employed to providelight to a variety of medical and industrial devices.

SUMMARY

In one aspect, a handheld lighting system is disclosed, which comprisesa handheld housing extending from a proximal end to a distal end, and aremovable and replaceable light module disposed at least partially inthe housing. The handheld lighting system further includes a powermodule that is coupled to the housing (e.g., it is at least partiallydisposed within the housing) and is electrically coupled to the lightmodule, e.g., through a pair of electrical leads, for providingelectrical power thereto.

The light module further includes an adapter disposed at the distal endof the housing for coupling the lighting system to a device having oneor more light guides, e.g., one or more optical fibers, for providinglight from the light module to those light guide(s), which can in turntransfer the light to a field of view for illumination thereof. In someembodiments, the adapter is removable and replaceable.

In some embodiments, the handheld housing includes at least a portionformed of a thermally conductive material, e.g., a metal such asaluminum. In some such embodiments, the thermally conductive portionincludes a corrugated external surface for facilitating transfer of heatgenerated by the light module and/or the power module to an externalenvironment. In some such embodiments, the corrugated external surfaceincludes a plurality of fins that increase its surface area, therebyenhancing heat dissipation through that surface. In some suchembodiments, the fins extend longitudinally and have a height in a rangeof about ⅛ inches to about ⅙ inches.

In some embodiments, the power module allows adjusting the intensity ofthe light generated by the light module. In some embodiments, the lightmodule includes a pair of electrical connectors (leads) protrudingthrough an internal wall of the housing for electrically connecting thelight module to the power module.

In some embodiments, the housing includes a first enclosure extendingfrom the distal end of the housing to an internal wall thereof forreceiving the light module, and a second housing extending from theinternal wall to a proximal end of the housing for receiving the powermodule.

In some embodiments, the housing includes a rotatable shell coupled tothe power module such that the rotation of the rotatable shell adjuststhe power supplied by the power module to the light module, therebychanging the intensity of the light generated by the light module. Insome such embodiments, the housing includes a heat sink portion to whichthe rotatable shell is coupled. By way of example, the rotatable shellcan include a spring-loaded ball that can engage within a retaininggroove provided in an inner wall of the heat sink portion. By way ofexample, the power module can include an adjustable potentiometerelectrically coupled to a light source of the light module andmechanically coupled to said rotatable shell such that a rotation of theshell results in a change of resistance of the potentiometer, therebyadjusting the intensity of the light generated by the light module.

In some embodiments, the light module includes a hollow chamberextending from a proximal end to a distal end, a lens positionedremovably and replaceably in the hollow chamber, the lens having a lensbody comprising an input surface for receiving light from the lightsource (e.g., an LED) and an output surface through which light exitsthe lens, said lens further comprising a collar encircling at leastpartially said lens body.

The light module can further include at least one sleeve disposed in thehollow chamber in contact with the lens collar for providing mechanicalsupport to the lens, and an optical window disposed in the hollowchamber and optically coupled to said output surface of the lens suchthat the light exiting the lens passes through the optical window beforeexiting the light module. The light source can be coupled to the hollowchamber at a proximal end thereof for providing light to said inputsurface of the lens. The optical window can be formed of any suitablematerial, such as sapphire, quartz, glass, etc.

In some embodiments of the above light module, a retaining window can becoupled releasably to the distal end of the hollow chamber, e.g., via aplurality of threads engaging with respective threads at the distal endof the hollow chamber. The retaining window can have an opening forcoupling to an adapter, which can in turn couple to a light guide so asto deliver the light from the light module to the light guide.

In some embodiments, a gasket can be disposed between the optical windowand the retaining window.

The light module can further include a printed circuit (PC) board onwhich the light source is mounted. The PC board can include a pluralityof electrical leads for applying electrical power to the light sourceand optionally controlling its operation.

A plate can be coupled to the distal end of the light module's housing,where the plate can have a plurality of openings through which theelectrical leads of the light module can extend for coupling to thepower module of the lighting system.

In some embodiments, the light module can include a shoulder for holdingthe lens within its housing. For example, the light module can includeat least one sleeve supporting the lens above the PC board. In someembodiments, a pair of sleeves are disposed on opposite sides of thelens collar, where one sleeve supports the lens above the PC board andthe other sleeve supports the optical window above the lens.

A plurality of different lenses can be employed in the light module. Byway of example, the lens can include a lens body comprising a proximalsection having said input surface and a distal section having saidoutput surface. The proximal section can include a substantiallyelliptical peripheral surface receiving at least a portion of the lightentering the lens body via said input surface and directing at leastsome of said received light via total internal reflection to said distalsection such that at least a portion of the light directed to the distalsection exits the lens body through said output surface. The peripheralelliptical surface is characterized by a proximal focal point and adistal focal point. In some embodiments, the peripheral surface isshaped such that the distal focal point is positioned external to thelens body, e.g. at a distance above the output surface of the lens. Inother embodiments, the distal focal point can be positioned in the lensbody, e.g., below the output surface or at the output surface. Further,in some embodiments, the proximal focal point is positionedsubstantially at or in proximity of the light source such that theelliptical surface transfers at least a portion of the light emitted bythe light source from the proximal focal point to the distal focalpoint. In many embodiments, the focal points are disposed on an opticalaxis of the lens, e.g., an axis about which the lens body isrotationally symmetric.

In some embodiments, the input surface includes a central convex portionand a peripheral portion surrounding said convex portion. In suchembodiments, the input surface can form a surface of a cavity configuredto receive at least partially the light source. In some suchembodiments, the proximal focal point can be positioned in the inputcavity.

In some embodiments, the peripheral portion of the input surface caninclude a proximal concave segment and a distal convex segment.

In some embodiments, the peripheral portion of the input surface isshaped such that at least a portion of the light entering the lens bodyvia said peripheral portion propagates to said peripheral ellipticalsurface to be reflected thereby. The peripheral portion of the inputsurface can be shaped such that at least about 80%, or at least about90%, or at least about 95% (and preferably 100%) of the light enteringthe lens body via the peripheral portion propagates to the peripheralsurface of the lens body to be reflected thereby.

In some embodiments, the convex portion of the input surface can exhibita positive optical power in a range of about 50 D to about 300 D. Insome such embodiments, at least a portion of the light entering the lensbody via said convex portion propagates to the output surface withoutstriking the peripheral surface.

In some embodiments, the input surface of the lens is configured tocapture at least about 70%, or at least about 80%, or at least about90%, or at least about 95% (and preferably 100%) of the light energyemitted by the light source. In some embodiments, the lens transfers thelight energy emitted by the light source from the light source to itsoutput surface with an efficiency of at least about 70%, or at leastabout 80%, or at least about 90% or at least about 95%.

In some embodiments, the light module of the lighting system couples thelight emitted by the light source to a light guide of a device to whichthe lighting system is coupled with an efficiency of at least about 30%,or at least about 40%, or at least about 50%, or at least about 60%, orat least about 70%, or at least about 80%, or at least about 90%.

In some embodiments, the output surface of the lens is substantiallyflat and is orthogonal to an optical axis of the lens.

The lens can be formed of a variety of different materials, such aspolymeric materials, or glass. Some examples of suitable materialsinclude, without limitation, polymethymethacylate (PMMA), polycarbonate,and silicone.

In some embodiments, the power module of the lighting system can bebattery operated, and in other embodiments, the power module can receiveAC line voltage and convert that voltage to a DC voltage suitable forapplication to the light source.

In some embodiments, the handheld lighting system can include a lightmodule, which includes a housing providing a hollow chamber extendingfrom a proximal end to a distal end, a lens positioned in said hollowchamber, said lens having a lens body comprising an input surface forreceiving light from a light source and an output surface through whichlight exits the lens body, said lens further comprising a collar atleast partially encircling said lens body. The light module can furtherinclude at least one shoulder on which said collar is seated, a lightsource coupled to said hollow chamber at said distal end for providinglight to said input surface of the lens. In some embodiments, theshoulder providing a seat for the lens can be in the form a sleevedisposed in the hollow chamber. In other embodiments, the shoulder canbe in the form a protrusion extending from an inner wall of the chamber.

In the above light module, the lens can further include a peripheralsurface for receiving at least a portion of the light entering the lensbody via the input surface and for directing the received light viatotal internal reflection to the lens's output surface. In some suchembodiments, the peripheral surface can have a truncated ellipticalshape characterized by an input focus and an output focus.

In some embodiments, the housing of the lighting system can include acorrugated external surface for facilitating transfer of heat generatedby at least one of the light module and the power module to an externalenvironment. By way of example, the corrugated surface can include aplurality of fins disposed on the external surface of the housing forenhancing the surface area thereof, thereby facilitating the dissipationof heat to the surrounding environment.

In a related aspect, an endoscope system is disclosed, which includes alight guide configured to be at least partially inserted into a subject,and a handheld lighting system optically coupled to said light guide forproviding light thereto. The handheld lighting system can include ahandheld housing extending from a proximal end to a distal end, a lightmodule disposed in said housing and having at least a light source forgenerating light, and a power module disposed within said housing andelectrically coupled to said light module for providing electrical powerthereto.

In some embodiments, the light module can be removably and replaceablydisposed within the housing of the lighting system.

The lighting system, including the light module, of the above endoscopecan be implemented in a manner discussed above.

In a related aspect, a device is disclosed, which includes a bodyhousing at least one light guide, and a handheld lighting system that ismechanically coupled to the body to be in optical coupling with thelight guide to provide light thereto. The handheld lighting system caninclude a removable and replaceable light module for generating light tobe delivered to the light guide of the device. The handheld lightingsystem, including the light module, can be implemented in a mannerdiscussed above. In some embodiments, the device can be any of anendoscope, a, illuminated surgical instrument, such as a surgicalheadlight, a video camera, a retractor, or a speculum.

Further understanding of various aspects of the invention can beobtained by reference to the following detailed description inconjunction with the drawings, which are described briefly below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic perspective view of a handheld lighting systemaccording to an embodiment of the present teachings,

FIG. 2A is a cross-sectional view of the handheld lighting systemdepicted in FIG. 1,

FIG. 2B is a partial cross-sectional view of a cavity provided at thedistal end of the lighting system for removably and replaceablyreceiving a light module and an adapter for coupling the lighting systemto a device for supplying light thereto,

FIG. 3 is a schematic exploded perspective view of the handheld lightingsystem depicted in FIG. 1,

FIG. 4 is another exploded view of the handheld lighting system,

FIG. 5A is a perspective exploded view of a light module suitable foruse in a handheld lighting system according to the present teachings,

FIG. 5B is a cross-sectional view of the light module depicted in FIG.5A,

FIG. 6 is an exploded view of the power module of the a handheldlighting system according to an embodiment of the present teachingsdepicting its various components,

FIG. 7 is an exemplary circuit diagram of the power module for adjustingthe intensity of an LED employed in the lighting system,

FIG. 8A is a cross-sectional view of an endoscope according to anembodiment in which a lighting system according to the present teachingsprovide light for illuminating a field of view,

FIG. 8B is perspective view of the endoscope depicted in FIG. 8A,

FIG. 9 is a perspective view of an endoscope according to an embodimenthaving a lighting system according to the present teachings, where thelight system receive AC line voltage,

FIG. 10A is a cross-sectional view of another light module that can beemployed in a lighting system according to the present teachings,

FIG. 10B is a perspective view of a lens employed in the light moduledepicted in FIG. 10A,

FIG. 11 is a top perspective view of a light module according to anotherembodiment,

FIG. 12 is another top perspective view of the light module depicted inFIG. 11,

FIG. 13 is a bottom perspective view of the light module depicted inFIG. 11,

FIG. 14 is a bottom view of the light module depicted in FIG. 11,

FIG. 15 is a perspective cross-sectional view of the light module,

FIG. 16 is a cross-sectional view of the light module,

FIG. 17 is a perspective exploded view of the light module,

FIG. 18 is a top perspective view of a portion of the housing of thelight module configured for holding the lens, and

FIG. 19 is a side cross-sectional view of the lens holder depicted inFIG. 18.

DETAILED DESCRIPTION

The present invention generally relates to a handheld illuminationsystem (herein also referred to as a handheld lighting system) that canefficiently transfer light emitted from a light source (typically anLED) to a light guide (e.g., optical fiber). In some embodiments, theillumination system can transfer light emitted by an LED to a lightguide with an efficiency greater than about 30%, or greater than about40%, or greater than about 50%, or greater than about 60%, or greaterthan about 70%, or greater than about 80%, or greater than about 90%, orgreater than about 95%. The illumination system includes a removable andreplaceable light module for generating light and a power module forsupplying electrical power to the light module as well as controllingits operation. As discussed above, a handheld illumination systemaccording to the present teachings can be coupled to a variety ofdifferent medical and industrial devices to provide light thereto. Inmany embodiments, at least a portion of the system's housing functionsas a heat sink to efficiently dissipate heat generated by any of thelight or the power module. As discussed in more detail below, thehandheld illumination system can collect light emitted by a light source(e.g., an LED) over a large angular spread (e.g., a divergence angle ofabout 180 degrees) and converge that light into a substantially smallerangular spread to efficiently couple that light to a light guide of adevice (e.g., an endoscope). Moreover, in some embodiments, the outputlight generated by a handheld illumination system according to thepresent teachings can exhibit a high color-over-angle uniformity.Various embodiments of a handheld lighting system according to thepresent teachings are discussed below.

Various terms are used herein consistent with their common meanings inthe art. By way of further explanation, a number of terms are definedbelow:

The term “optical power” is used herein consistent with its commonmeaning in the art to refer to the degree to which an optical componentor surface converges or diverges incident light and is equal to thereciprocal of the focal length of the component of the surface.

The term “elliptical surface” or similar terms as used herein refer to asurface that is shaped as a section of an ellipse. In other words, anelliptical surface is in the form of a truncated ellipse.

The term “numerical aperture” is used herein consistent with its commonmeaning in the art to refer to a dimensionless number that characterizesthe range of angles over which an optical component or system can emitor accept light.

The term “about” as used herein is intended to indicate a variation ofat most 10% around a numerical value.

The term “substantially” as used herein is intended to indicate adeviation of less than 5% relative to a complete state or condition.

With reference to FIGS. 1, 2A, 2B, 3, 4, 5A and 5B, a handheld lightingsystem 2000 according to an embodiment of the present invention includesa handheld housing 2001 that extends from a proximal end (PE) to adistal end (DE) and is composed of a proximal section 2001 a (hereinalso referred to as a rotatable shell) and a distal section 2001 b(herein also referred to as the heat sink portion), which are releasablycoupled to one another. The handheld lighting system 2000 also includesan endcap 2001 c. In this embodiment, the heat sink portion 2001 b isformed of a thermally conductive material, such as aluminum, to functionas a heat sink for transferrin heat generated within the housing to theexternal environment. In this embodiment, the rotatable shell 2001 a andthe endcap 2001 c can be formed of a plastic, such as acrylonitrilebutadiene styrene (ABS). In other embodiments, the heat sink, therotatable shell and the endcap can be formed of the same material, e.g.,aluminum.

The heat sink portion 2001 b includes an enclosure 2002, which iscomposed of two substantially cylindrical hollow portions 2002 a and2002 b with different diameters. A stand-alone light module 2004 isremovably and replaceably disposed in the hollow portion 2002 a. Thelight module 2004 includes a housing 2005 in which various components ofthe light module are disposed. In particular, the light module 2004includes a lens 2006 having a proximal section 2006 a with an inputsurface 2008 that forms a cavity for receiving light from a lightemitting diode 2010, which is mounted on a printed circuit (PC) board2012. In this embodiment, the input surface includes a central convexportion 2008 a surrounded by a peripheral portion 2008 b, where theperipheral portion 2008 b includes a proximal concave segment (A) and adistal convex segment (B). In some embodiments, the central convexportion 2008 a can exhibit an optical power in a range of about 50 D toabout 300 D.

In this embodiment, the central convex portion of the input surfaceprovides a positive optical power, which results in the convergence ofthe light rays entering the lens body through that surface to a focalpoint (herein also referred to as the convergence point) typicallylocated within the lens body, e.g., a small distance below the lens'output surface. In some other embodiments, the convex portion isconfigured such that its focal point (i.e., the point at which the lightrays refracted by that portion converge) is external to the lens. By wayof example, the focal point of the convex portion may be within theproximal end of a light guide coupled to the lens, or external to boththe lens and the light pipe such that the light rays diverging form thefocal point to illuminate the input face of the light pipe would exhibita maximum angular spread corresponding to that of a solid anglesubtended by the input face of the light guide. By way of example, insome such embodiments, the focal point of the convex portion can besubstantially coincident with the distal focal point of the ellipticalperipheral surface.

The proximal portion 2006 a further includes an elliptical peripheralsurface 2016 that directs the light incident thereon via total internalreflection to the output surface of the lens 2014. The lens 2006 furtherincludes a distal section 2006 b having an output surface 2014 throughwhich the light exits the lens and a peripheral surface 2013, which isin the form of a truncated cone in this embodiment, though other shapescan also be utilized.

The peripheral elliptical surface 2016 is characterized by an inputfocal point f1 and an output focal point f2, which are positioned on theoptical axis (OA) of the lens in this embodiment. The peripheralelliptical surfaces transfers at least a portion of the light emitted bythe light source 2010 from the input focal point to the output focalpoint. In this embodiment, the input focal point is positioned withinthe input cavity and the output focal point is positioned external tothe lens at a distance relative to the output surface of the lens. Insome embodiments, the position of the output focal point is selectedsuch that the light rays diverging from the output focal point exhibitan angular spread across the input face of a light guide coupled to thelens that maximizes the coupling of the light into the light guide. Forexample, the diverging beam can have an angular spread commensurate withan input numerical aperture of the light guide. For example, thedistance between the output focal point 1240 and the output surface ofthe lens may be in the range of about 4 mm to about 6 mm, though othervalues can also be used depending, for example, on the lens size and/orparticular application in which the lens is employed.

A plurality of leads 2017 a/ 2017 b allow coupling the light module to apower module 2028, which is described in more detail below. A pair ofsleeves 2013 a/ 2013 b protect the leads 2017 a/ 2017 b.

The lens 2006 further includes a collar 2018 (herein also referred to asa flange) that encircles the lens body. While in this embodiment thecollar 2018 partially encircles the lens body, in other embodiments, thecollar can fully encircle the lens body. The lens 2006 is mechanicallysecured over the PC board 2012 via a pair of sleeves 2020 and 2022(herein also referred to as spacers) disposed, respectively below andthe above the lens collar 2018 and in contact therewith. An opticalwindow 2024 is disposed over the output surface 2014 of the lens and issupported by the sleeve 2022.

The optical window 2024 is preferably in contact with the output surface2014 of the lens to ensure good optical coupling between the window andthe lens. In some embodiments, a refractive index matching material,such as a gel, may be disposed between the output surface of the lensand the optical window to minimize optical loss as light exiting thelens couples into the window to pass therethrough. The optical window2024 can protect the output surface of the lens. In addition, in someembodiments, the optical window 2024 can adjust one or morecharacteristics of the light exiting the lens. By way of example, theoptical window 2024 can be selected to function as a filter, e.g., abandpass filter, to allow passage of certain wavelengths of the lightexiting the lens while blocking other wavelengths. For example, suchfiltering of the light exiting the lens can be used to adjust the colortemperature of the light. The optical window 2024 can be formed of avariety of different materials, such as sapphire, quartz, glass, etc. Insome embodiments, the material from which the optical window 2024 isformed is substantially transparent to visible radiation. In otherembodiments, the optical window 2024 may be substantially transparent toradiation in another region of the electromagnetic spectrum. By way ofexample, in some embodiments in which the light module emits radiationin the infrared region of the electromagnetic spectrum, the opticalwindow 2024 can be formed of high density polyethylene.

The light module 2004 further includes a retaining window 2025 (hereinalso referred to as ring window) that is removably and replaceablyattached to the upper end of the light module's housing 2005. Inparticular, in this embodiment, the window ring 2025 includes aplurality of external threads 2025 a that can engage with a plurality ofinternal threads 2005 a provided at the upper end of the module'shousing. A gasket 2026 is disposed between the retaining window and theoptical window. The retaining window, the optical window and the gasketcooperatively seal the light module from the external environment.

The handheld lighting system 2000 further includes an adapter 2027(herein also referred to as “light guide adapter”) that can be removablyand replaceably received in the upper hollow cylindrical portion 2002 bof the enclosure 2002 provided proximate the distal end of the housing2001 to allow coupling the lighting system to a plurality of differentdevices employing, for example, light guides for illuminating a field ofview. In this embodiment, the light guide adapter can include aplurality of threads 2027 a that can engage with a plurality of threads2019 provided in the inner wall of the upper hollow cylindrical portion2002 b. In other embodiments, the light guide adapter 2027 can besnapped into the enclosure 2002 b. A gasket 2011 is positioned betweenthe adapter 2027 and the light module 2004 to provide a sealtherebetween.

Advantageously, the handheld system 2000 can be coupled to a variety ofdifferent devices, e.g., by simply changing the light guide adapter2027, to provide light to light guides employed in such devices forilluminating a field of view. Some examples of such devices include,without limitation, endoscopic systems, illuminated surgicalinstruments, such as a surgical headlight, a video camera, a retractor,a speculum, and other devices requiring high intensity, high qualitylight.

With reference to FIGS. 2A, 3, and 6, the handheld lighting system 2000further includes the power module 2028 that is disposed in the housing2001 to provide electrical power to the light module 2004 and controlits operation. More specifically, in this embodiment, a portion of thepower module is accommodated within the rotatable shell 2001 a andanother portion thereof is accommodated within a hollow enclosure 2000 dprovided within the heat sink portion 2001 b of the housing 2001. Inthis embodiment, the power module 2028 is secured to the housing via ascrew 2029 that protrudes through an inner wall 2030 of the housing.

The power module 2028 includes a casing 2032 (herein also referred to asa sled) for housing at least a battery 2034 for providing power to theLED 2010. The power module 2028 further includes a printed circuit board2036 on which electronic components for controlling the operation of thelight module are mounted, as discussed in more detail below. Inparticular, a potentiometer/switch 2038 is mounted on a switch printedcircuit board 2040, which is in turn mounted on the PC board 2036. Aspring 2042 facilitates forming an electrical contact with the battery2034 when the switch 2038 is used to switch on the illumination system.The potentiometer 2038 includes a shaft 2038 a that allows adjusting itsOhmic resistance, which in turn allows adjusting the intensity of thelight emitted by the LED 2010, as discussed in more detail below.

The power module 2028 further includes a printed circuit board mount2044 having an opening 2044 a through which the shaft of thepotentiometer can extend. In addition, the shaft of the potentiometerextends into an opening 2046 provided within the endcap 2001 c of thehousing to rotatably couple the potentiometer's shaft to rotatable shell2001 a. A spacer 2046 and a static seal 2048 are disposed between thehousing end cap 2001 c and the PC board mount 2044, where the staticseal helps sealing the power module from the external environment.

In this embodiment, the rotatable shell 2001 a is rotatably coupled tothe heat sink portion 2001 b of the housing. More specifically, theouter wall of the heat sink portion includes a circumferential groove2050 at its proximal end, where the groove extends 300 degrees aroundthe housing. The rotatable shell 2001 a includes a spring loaded ball2052 that can engage with the groove 2050. The groove 2050 includes adetent mechanism at each of its extreme ends for capturing the ballthereby limiting the rotation of the rotatble shaft.

A user can apply a rotational torque to the rotatable shell 2001 a todisengage the spring loaded ball from the detent mechanism and rotatethe shell, which in turn causes the rotation of the potentiometer'sshaft via the endcap 2046. The rotation of the potentiometer's shaft cancause a change in its resistance, which in turn results in adjusting theintensity of the light emitted by the LED 2010. In this embodiment, apiece of wire 4 disposed in a groove of the potentiometer shaft 2038 ahelps with coupling of the shaft to the endcap 2046.

A dynamic seal 2054 is provided between the rotatable shell 2001 a andthe heat sink portion 2001 b to facilitate sealing the variouscomponents within the housing while allowing the rotation of the shell2001 a for adjusting the intensity of the light emitted by the LED 2010.

With continued reference to FIG. 5, the power module 2028 furtherincludes a pair of wires 1 and 2, and the associated components 3 thatallow forming an electrical contact between the battery 2034 and thecircuit board 2036.

FIG. 6 schematically shows a circuit diagram of the electroniccomponents within the power module 2028, at least some of which aremounted on the PC board 2026, supplying electric power to the LED 2010and adjusting the intensity of the emitted light. As noted above, thebattery 2034 provides electrical power for the LED 2010. In thisembodiment, the battery provides a voltage of 3.7 volts and 750milliamperes of current. A transistor Q1 provides protection againstpositioning the battery in a reverse direction. A switch (R13-NC/R13C)allows switching the power to LED 2010. The potentiometer (R13-1, 2, 3)adjusts the current applied to the LED 2010 by shunting current from thefeedback network (R1, R2, R3, C4, and C6). The output current (Iout) ofthe switching regulator U1 (LTC3112EDHD) mirrors the LED current, whereU1 can ramp up the LED current until the voltage at the FB pin reachesthe feedback voltage. A low-drop-out voltage regulator U2, R20, and R21set a stable voltage so that U1 can regulate the LED current all the wayto zero (e.g., to keep the current properly regulated as the batteryvoltage drops). The resistor R4 sets the upper limit on the LED current(about 1.03 A). The value of this resistor can be increased to limit theLED current to less than 1 A. In this embodiment, the capacitor C5 andthe resistors R6 and R7 set the maximum output voltage to 6 V, whichlimits the voltage when the LED is not installed in the handheld system.Further, U1 and the inductor L1 handle the buck/boost switching tomaintain the LED current in face of falling battery voltage.

As noted above, the heat sink portion 2001 b not only provides a housingfor the light module and a portion of the power module, it alsofacilitates the transfer of heat generated by one or more componentswithin the housing to the external environment, thereby ensuring thatthe temperature of outer surface of the housing remains below a desiredthreshold. With reference to FIGS. 1 and 3, the outer surface of theheat sink portion 2001 b of the housing 2001 includes a plurality offins 2064, which facilitate the transfer of heat generated by one ormore components within the housing (e.g., the LED 2010) to the externalenvironment. More specifically, the fins 2064 increase the externalsurface area of the heat sink portion, thereby enhancing the dissipationof heat to the external environment. In this embodiment, the fins 2064are disposed longitudinally along the outer surface of the heat sinkportion (i.e., parallel to an optical axis (OA) of the illuminationsystem). The use of longitudinal fins can also provide manufacturingadvantages as it allows the fabrication of the housing using extrusiontechniques.

While in this embodiment, twelve fins are employed, the number of finsin other embodiments can be different. In some implementations, thedepths of the valleys between adjacent fins (or in other words theheights of the fins) can be, for example, in a range of about ⅛ inchesto about ⅙ inches. In some embodiments, the total effective surface areaof the external surface of the heat sink portion, i.e., the areaeffective in dissipating heat, can be at least about 10 square inches.In some implementations, the efficiency of heat dissipation by the heatsink ensures that the temperature of the outer surface of the housingremains below about 115° F. when the lighting system is in use. In somecases, maintaining the temperature of the housing at or below themaxiumum temperature can be achieved even when the LED 2010 is operatedat a current of 1 ampere.

In some embodiments, not only the heat sink portion 2001 b but also therotatable shell 2001 a can be formed of a thermally conductive material,e.g., a metal such as aluminum, to facilitate transfer of heat generatedby one or more components within the housing to the externalenvironment. Further, in such embodiments, the rotatable shell caninclude a plurality of fins for enhancing heat dissipation.

As noted above, in some embodiments, the handheld illumination systemcan be coupled to a medical or industrial device to provide light, forexample, to one or more light guides of the device for illuminating afield of view. By way of example, FIGS. 8A and 8B schematically depictan endoscope 2056 having an endoscope body 2058 including a flexibleelongated element 2060 extending from a proximal end (PE) to a distalend (DE) in which a plurality of optical fibers 2061 are disposed. Theendoscope 2056 can also include other optical components such as one ormore lenses, cameras, and image processing circuitry (not shown in thefigure) in a manner known in the art. The elongated element isconfigured for insertion into a patient. The exemplary endoscope 2056also includes a handle 2062 for manipulating the device.

The handheld illumination system 2000 according to the present teachingsis coupled to the endoscope body so as to provide light to the opticalfibers disposed in the flexible element 2060. More specifically, thehandheld illumination system 2000 is coupled to the endoscope body viathe light guide adapter 2027. A light guide connector 2063 canfacilitate optically coupling the light module 2004 to the opticalfibers to provide light to the optical fibers, which can in turntransmit the light to the distal end (DE) of the flexible elongatedelement 2060 for illuminating a field of view.

In use, the flexible element 2060 can be at least partially insertedinto a patient and the external illumination system 2000 can be employedto provide light to the light guide(s) disposed in the elongated element2060, which in turn guide the light to the distal end of the elongatedelement through which the light exits the endoscope to illuminate afield of view.

While in some embodiments, a handheld lighting system according to thepresent teachings can be battery operated, in other embodiments thehandheld lighting system can be supplied with AC line power. By way ofexample, FIG. 9 schematically depicts an endoscope 3000 according to anembodiment of the present teachings, which includes a handheld lightingsystem 3002 that is powered by AC (alternating current) line voltage.The handheld lighting system 3002 is similar to the handheld lightingsystem 2000 discussed above except that its power module includes anAC-to-DC converter that converts the AC line voltage to an appropriateDC voltage for application to an LED of a light module disposed in thehousing.

One advantage of a handheld lighting system according to the presentteachings is that it can be used with a variety of different lightmodules. For example, with reference to FIGS. 10A and 10B, a lightmodule 300 according to another embodiment includes a housing 301 inwhich a lens 302 can be removably and replaceably positioned. The lens302 includes an input surface 304 that is optically coupled to an LED306, which is mounted on a printed circuit board 308, to receive lighttherefrom. The lens 302 further includes an output surface 310 (which issubstantially flat in this embodiment) through which light exits thelens. The lens 302 also includes a peripheral surface 312 that receivesat least a portion of the light entering the lens through its inputsurface and directs the light incident thereon via total internalreflection to the output surface. Similar to the previous embodiment,the peripheral surface 312 is in the form of a truncated ellipse thatincludes an input focus f1 on or in close proximity of the LED 306 andan output focus f2 that is external to the lens at a distance, e.g., ina range of about 4 mm to about 6 mm, above the lens' output surface 310.A collar (herein also referred to as flange) 314 partially encircles thelens body and facilitates the positioning of the lens within the housing301, as discussed in more detail below.

More specifically, a sleeve 316 in contact with a lower surface of thecollar 314 supports the lens 312 above the printed circuit board 308.Another sleeve 318 is seated on an upper surface of the lens collar 314and supports an optical window 320 at a distance D above the outputsurface 310 of the lens. The optical window 320 can be implemented, forexample, in a manner discussed above in connection with the previousembodiment.

A retaining window 322 is releasably coupled to the housing via aplurality of threads 322 a, which engage with respective threadsprovided in the inner surface of the housing 301. A gasket 322positioned between the retaining window 322 and the optical window 320can provide a seal. Similar to the previous embodiment, the retainingwindow 322 can be connected to an adapter 326 of a light guide (notshown) for optically coupling the light module 300 to the light guide.The light module 300 includes a pair of electrical leads 300 a and 300 bfor connecting the light module to a source of electrical power, such asone or more batteries.

In some embodiments, a handheld lighting system according to the presentteachings can include a light module having a housing that provides ashoulder, e.g., in the form of a protrusion extending from an inner wallof the module's housing, for seating a lens. By way of example, withreference to FIGS. 11-19, a light module 1 according to the anotherembodiment, which can be removably and replaceably inserted within thehousing includes an external housing 5 having a lens holder 17 and awindow ring 8, which are releasably coupled to one another. In thisembodiment, the lens holder 17 contains a cylindrical internal channel19 with a top opening 20 and a bottom opening 21. The lens holder 17contains an internal shoulder 22 for holding an optical lens 3 withinthe internal channel 19. The lens holder 17 further includes a secondinternal shoulder 23 for holding a sapphire window 14 in substantiallyplanar arrangement over an output surface 4 of the optic lens 3. Thebottom opening 21 of the lens holder 17 permits any wiring or powersources to be operatively connected to the LED 2.

In this embodiment, the optical lens 3 is formed of a single piece oftransparent material that allows the passage of the light emitted by theLED 2 therethrough. For example, the lens 3 may be formed of glass,plastic, or sapphire. The lens 3 includes a proximal (orlight-receiving) section 9 having an input surface 10 for receivinglight from the 2, and a distal for light-outputting) section 6 having asubstantially flat output surface 4. The optical lens 3 also includes acollar 8 that can be seated on the internal shoulder 22 for being heldwithin the lens holder 17, The input surface 10 includes a peripheralcurved surface 12 and a central convex surface 13 that collectively forma cavity 11. The optical lens 3 includes a peripheral elliptical surfacethat reflects the light incident thereon via total internal reflection.

The window ring 18 includes a cylindrical internal channel 24 with a topopening 25 and a bottom opening 26. The window ring 18 contacts a topsurface 15 of the sapphire window 14 to secure the sapphire windowagainst the internal shoulder 23. In this embodiment, the bottom surfaceof the window ring 18 and the top surface of the lens holder 17 arethreaded for releasable attachment to one another.

The external housing 5 protects the LED 2, the elliptical optic lens 3,and the sapphire window 14 from the external environment. The resilientexternal housing 5 permits the module 1 to be attached to theillumination device without fear of misaligning or damaging the internalLED 2, the elliptical optic lens 3, and the sapphire window 14. In someembodiments, the lens holder 17 and the window ring 18 may be formed ofmetals, alloys, or plastics.

In some embodiments, the module 1 may be attached to a source of powerfor supplying electrical power to the LED 2 and any circuitry to providethe correct voltage to the LED 2, both of which are well known in theart. By way of example, the source of power can be one or morebatteries, or AC line power.

Those having ordinary skill in the art will appreciate that variouschanges can be made to the above embodiments without departing from thescope of the invention. Further, the elements disclosed in connectionwith one embodiment can be employed in other embodiments.

What is claimed is:
 1. A handheld lighting system, comprising: ahandheld housing extending from a proximal end to a distal end, a lightmodule disposed removably and replaceably in said housing and having atleast a light source for generating light, said light module having anadapter disposed at said distal end of the housing for coupling thelight module to a light guide such that the light guide receives thelight generated by the light module, a power module disposed within saidhousing and electrically coupled to said light module for providingelectrical power thereto wherein said light module comprises: a hollowchamber extending from a proximal end to a distal end, a lens positionedin said hollow chamber, said lens having a lens body comprising an inputsurface for receiving light from the light source and an output surfacethrough which light exits the lens, said lens further comprising acollar encircling at least partially said lens body, at least one sleevedisposed in said hollow chamber in contact with said collar forproviding mechanical support to said lens, an optical window disposed insaid hollow chamber and optically coupled to said output surface of thelens such that the light exiting the lens passes through the windowbefore exiting the light module, and wherein the light source is coupledto said hollow chamber at said distal end for providing light to saidinput surface of the lens, and wherein said lens comprises: the lensbody comprising a proximal section having said input surface and adistal section having said output surface, wherein said proximal sectionfurther comprises: a substantially elliptical peripheral surfacereceiving at least a portion of the light entering the lens body viasaid input surface and directing at least some of said received lightvia total internal reflection to said distal section such that at leasta portion of the light directed to the distal section exits the lensbody through said output surface.
 2. The handheld lighting system ofclaim 1, wherein said adapter is removable and replaceable.
 3. Thehandheld lighting system of claim 1, wherein said handheld housingcomprises a corrugated external surface for facilitating transfer ofheat generated by at least one of the light module and the power moduleto an external environment.
 4. The handheld lighting system of claim 1,wherein said power module allows adjusting an intensity of the lightgenerated by said light module.
 5. The handheld lighting system of claim1, wherein said light guide comprises an optical fiber.
 6. The handheldlighting system of claim 1, wherein said light module comprises a pairof electrical connectors protruding through an internal wall of saidhousing for electrically connecting the light module to said powermodule.
 7. The handheld lighting system of claim 6, wherein said housingcomprises a first enclosure extending from said internal wall to saiddistal end for receiving said light module.
 8. The handheld lightingsystem of claim 7, wherein said housing further comprises a secondenclosure extending from said internal wall to said proximal end forreceiving said power module.
 9. The handheld lighting system of claim 1,wherein said power module comprises a rotatable outer shell, wherein arotation of the shell results in adjusting an intensity of the lightgenerated by said light module.
 10. The handheld lighting system ofclaim 9, wherein said housing comprises a retaining groove for engagingwith an end of said outer shell for locking said power module to saidhousing.
 11. The handheld lighting system of claim 9, wherein said powermodule comprises an adjustable potentiometer electrically coupled tosaid light source and mechanically coupled to said rotatable shell suchthat a rotation of the shell results in a change of resistance of saidpotentiometer, thereby adjusting the intensity of the light generated bythe light module.
 12. The handheld lighting system of claim 1, whereinsaid housing comprises a thermally conductive material.
 13. The handheldlighting system of claim 11, wherein said housing comprises aluminum.14. The handheld lighting system of claim 1, wherein said light sourcecomprises a light emitting diode (LED).
 15. The handheld lighting systemof claim 1, wherein said window comprises any of a sapphire window, aquartz window and a glass window.
 16. The handheld lighting system ofclaim 15, further comprising a plurality of external threads disposed atsaid distal end of the hollow chamber.
 17. The handheld lighting systemof claim 16, further comprising a retaining window adapted forreleasably coupling to said distal end of the hollow chamber.
 18. Thehandheld lighting system of claim 17, wherein said retaining windowcomprises a plurality of internal threads adapted for engagement withsaid external threads at the distal end of the hollow chamber.
 19. Thehandheld lighting system of claim 18, wherein said retaining windowincludes an opening for coupling to the adapter for coupling to thelight module to the light guide.
 20. The handheld lighting system ofclaim 19, further comprising a washer disposed between said opticalwindow and said retaining window.
 21. The handheld lighting system ofclaim 20, further comprising a printed circuit board on which the LED isdisposed.
 22. The handheld lighting system of claim 21, wherein saidboard comprises a plurality of electrical leads for applying electricalpower from said power module to said LED.
 23. The handheld lightingsystem of claim 22, further comprising a plate coupled to said distalend of the hollow chamber, said plate having a plurality of openingsthrough which said electrical leads extend for coupling to said powermodule.
 24. The handheld lighting system of claim 23, wherein said atleast one sleeve comprises a pair of sleeves disposed on opposite sidesof said collar.
 25. The handheld lighting system of claim 1, whereinsaid peripheral elliptical surface is characterized by a proximal focalpoint and a distal focal point and is shaped such that said distal focalpoint is positioned in said distal section of the lens body.
 26. Thehandheld lighting system of claim 25, wherein said distal focal point ispositioned at a distance below said output surface such the lightreceived at said distal focal point via reflection at the ellipticalsurface diverges towards said output surface within a solid anglesubtended by said output surface.
 27. The handheld lighting system ofclaim 26, wherein said proximal focal point of said elliptical surfaceis positioned substantially at said light source such that theelliptical surface transfers at least a portion of light emitted by saidlight source from said proximal focal point to said distal focal point.28. The handheld lighting system of claim 27, wherein said input surfacecomprises a central convex portion and a peripheral portion surroundingsaid central convex portion.
 29. The handheld lighting system of claim28, wherein said input surface forms a surface of a cavity configured toreceive at least partially the light source.
 30. The handheld lightingsystem of claim 29, wherein said proximal focal point of the ellipticalsurface is disposed within said cavity.
 31. The handheld lighting systemof claim 30, wherein said peripheral portion of the input surface isshaped such at least a portion of the light entering the lens body viasaid peripheral portion propagates to said peripheral elliptical surfaceto be reflected thereby.
 32. The handheld lighting system of claim 31,wherein said peripheral portion of the input surface is shaped such thatat least about 80% of the light entering the lens body via saidperipheral portion propagates to said peripheral surface of the lensbody.
 33. The handheld lighting system of claim 32, wherein said convexportion is characterized by a positive optical power in a range of about50 to about 300 D.
 34. The handheld lighting system of claim 33, whereinat least a portion of the light entering the lens body via said convexportion propagates to said output surface.
 35. The handheld lightingsystem of claim 34, wherein said convex portion is configured such thatthe light entering said lens body via the convex portion propagates tosaid output surface without striking said peripheral surface.
 36. Thehandheld lighting system of claim 35, wherein said peripheral portion ofthe input surface comprises a proximal concave segment and distal convexsegment.
 37. The handheld lighting system of claim 36, wherein saidinput surface is configured to capture at least about 80% of the lightemitted by said light source.
 38. The handheld lighting system of claim37, wherein said input surface is configured to capture at least about90% of the light emitted by said light source.
 39. The handheld lightingsystem of claim 38, wherein said proximal section and said distalsection are disposed about an optical axis of said lens body.
 40. Thehandheld lighting system of claim 39, wherein said output surface issubstantially flat.
 41. The handheld lighting system of claim 39,wherein said output surface is substantially orthogonal to said opticalaxis.
 42. The handheld lighting system of claim 41, wherein said collaris disposed at a boundary between said proximal section and said distalsection.
 43. The handheld lighting system of claim 1, wherein said lensbody comprises a polymeric material.
 44. The handheld lighting system ofclaim 43, wherein said polymeric material is any of polycarbonate,polymethylmethacrylate (PMMA) and high density polyethylene.
 45. Thehandheld lighting system of claim 1, wherein said power module isbattery operated.
 46. The handheld lighting system of claim 1, whereinsaid power module is powered by AC line power.